Synthesis and Highly Enantioselective Hydrogenation of Exocyclic Enamides: (<i>Z</i>)-3-Arylidene-4-acetyl-3,4-dihydro-2<i>H</i>- 1,4-benzoxazines

Highly enantioselective hydrogenation of exocyclic enamides, (Z)-3-arylidene-4-acyl-3,4-dihydro-2H-benzoxazines, was achieved in up to 98.6% ee by using Rh/(R,R)-Me-Duphos complex as the catalytic system. The absolute configuration of the product was assigned as R by chemical interrelations

Synthesis and Highly Enantioselective Hydrogenation of Exocyclic Enamides: (<i>Z</i>)-3-Arylidene-4-acetyl-3,4-dihydro-2<i>H</i>- 1,4-benzoxazines

Highly enantioselective hydrogenation of exocyclic enamides, (Z)-3-arylidene-4-acyl-3,4-dihydro-2H-benzoxazines, was achieved in up to 98.6% ee by using Rh/(R,R)-Me-Duphos complex as the catalytic system. The absolute configuration of the product was assigned as R by chemical interrelations

Highly Enantioselective Iridium-Catalyzed Hydrogenation of Heteroaromatic Compounds, Quinolines

The highly enantioselective hydrogenation of quinoline derivatives is developed using [Ir(COD)Cl]2/(R)-MeO-Biphep/I2 system, and this methodology has been applied to the asymmetric synthesis of three naturally occurring alkaloids angustureine, galipinine, and cuspareine. This method provided an efficient access to a variety of optically active tetrahydroquinolines with up to 96% ee

Tandem Ring-Opening/Closing Reactions of <i>N</i>-Ts Aziridines and Aryl Propargyl Alcohols Promoted by <i>t</i>-BuOK

t-BuOK was found to be an effective promoting reagent for tandem ring-opening/closing reactions of various N-Ts aziridines and aryl propargyl alcohols to afford dihydroxazine derivatives in moderate to good yields. A plausible reaction mechanism has been proposed